wrf_interp_1d

Linearly interpolates a one-dimensional variable in the vertical.

Prototype

	function wrf_interp_1d (
		v_in   : numeric,  
		z_in   : numeric,  
		z_out  : numeric   
	)

	return_val [dimsizes(z_out)] :  float or double

Arguments

One-dimensional array to interpolate in the vertical. This array's rightmost dimension is nz.

One-dimensional array representing the vertical structure (height/pressure) of the v_in array. This array has the same dimensionality as v_in.

An array with constant height to interpolate to. Must be of the same type (height/pressure) as z_in.

Return value

The return array will be the same dimensionality as z_out. The return type will be double of any of the input is double, and float otherwise.

Description

Linear interpolation in the vertical. Vertical indices can increase or decrease with height.

If v_in has attributes "description" or "units", they will be returned with the output variable. The "description" attribute will be set to " " if v_in doesn't contain this attribute.

See Also

wrf_interp_2d_xy, wrf_interp_3d_z, wrf_user_intrp3d

Examples

Example 1

    a = addfile("wrfout_d01_2000-01-24_12:00:00.nc","r")
    time = 0
    
  ; Temperature
    t = a->T(time,:,:,:)          ; perturbation potential temperature (theta-300)
    theta = t + 300.              ; potential temperature
    p  = a->P(time,:,:,:)
    pb = a->PB(time,:,:,:)
    pf = p + pb                    ; full pressure
    tk = wrf_tk (pf, theta)        ; temperature in Kelvin

  ; Height in the model
    ph   = a->PH(time,:,:,:)        ; perturbation geopotential
    phb  = a->PHB(time,:,:,:)       ; base-state geopotential
    tmp  = (ph+phb)/9.81            ; On full (w) levels
    dimv = dimsizes(tmp)
    z = 0.5*(tmp(0:dimv(0)-2,:,:)+tmp(1:dimv(0)-1,:,:))    ; On half (mass) levels
    z@description = "height"
    z@units = "m"
    
    lat = a->XLAT(time,:,:)        ; latitude
    lon = a->XLONG(time,:,:)        ; longitude
   
  ; Radiosonde observation
    radiosonde = asciiread("raob_OUN.txt",(/2,39/),"float")
    z_raob = radiosonde(0,:)    ; height in radiosonde
    z_raob@_FillValue = -999.99 ; missing value
    
  ; Station information (OUN - Norman, OK)
    olat = 35.2
    olon = -97.4
    
  ; Find the closest point to the radiosonde site in WRF grids
    obsij = wrf_latlon_to_ij(lat,lon,olat,olon)
    obsi = obsij(0)
    obsj = obsij(1)
    
    tin = tk(:,obsi,obsj)
    zin = z(:,obsi,obsj)
  
  ; Interpolation
    t_wrf = wrf_interp_1d (tin,zin,z_raob)
    t_wrf@_FillValue = -999.99
    print(t_wrf)